The present invention relates to gas lighters, and relates more particularly to a safety knob for a gas lighter which can be moved between the locking position to stop the gas lever from operating, and the unlocking position to let the gas lever to be operated.
Regular disposable gas lighters are commonly comprised of a butane well molded from transparent plastics to hold a fuel gas, a holder frame covered on the top open side of the butane well to hold a dip tube and a valve rod, and a casing mounted on the holder frame to hold a gas lever and a striker wheel. When the gas lever is depressed, the valve rod is lifted to release the fuel gas, and therefore the striker wheel can be operated to ignite the fuel gas. This structure of disposable gas lighter is functional, however the gas lever may be easily triggered to release the fuel gas by an error. In order to prevent the happening of an accident, there are certain countries executing the rule of defining a safety requirement on disposable gas lighters. Various safety devices for use with gas lighters have been developed. Exemplars are shown in U.S. Pat. No. 5,186,618 issued to SHIKE; U.S. Pat. No. 5,205,729 issued to IWAHORI; U.S. Pat. No. 5,165,886 issued to FRIGIERE; U.S. Pat. No. 5,090,893 issued to FLORIOT. These disclosures commonly show the use of moving a safety knob the locking position and the unlocking position to stop the release of the fuel gas when the gas lever is triggered by an error. However, when the safety knob is moved into the locking position, the gas lever will be forced upwards at a short distance, causing a certain amount of the fuel gas released. Furthermore, the safety knob return mechanisms of the gas lighters disclosed are commonly complicated, and therefore they are difficult to install and tend to be damaged.